computergenious asked:


A 30 ton rail car and a 70ton rail car, initially at rest, are connected together with a giant but massless compressed spring between them. When released, the 30ton car is pushed away at a speed of 4.6 m/s relative to the 70ton car. What is the speed of the 30ton car relative to the ground?

Lorenzo

One Response to “What is the speed of the 30 ton car relative to the ground?”

1. Waheed on February 22nd, 2010 12:15 pm

   30 x v1 = 70 x v2 and v1 + v2 = 4.6
   v1 = ( 70/30) v2 = 2.33 v2
   2.33 v2 + v2 = 4.6
   v2 = 1.38

   v1 = 4.6 - 1.38 = 3.22 m/s ans